基于PZT结Lamb波方向算法的损伤定位方法

基于Lamb波在板中的传播特性,针对复合材料的损伤检测,提出一种新型的损伤定位方法。该方法采用3个压电陶瓷片( piezoelectric transducers,简称PZT)组成PZT结,通过从各PZT中提取出损伤散射信号,找到其损伤波包到达的时间差,并依据Lamb波的传播速度得到位移差。首先,结合PZT结中各PZT的几何位置,具体推导出损伤方向算法,运用方向算法找到Lamb波在损伤位置发生散射后的其中一个传播方向,通过传播方向的交点来实现损伤位置的判定;其次,分析了互相关理论的基本原理,并运用互相关算法提取出损伤散射信号;最后,在碳纤维增强树脂基复合材料薄板上对该算法进行实验验证,求出了损伤方向以及损伤位置。验证结果表明,该方法能够对复合材料损伤进行有效的定位。     

维罗绒仿扎染工艺

维罗绒织物厚重挺括,仿扎染工艺采用泼洒染液、喷后压皱,形成自然的冰纹效应;再经高温高压汽蒸,形成以主色调为主,渗透色为辅的色彩斑斓的仿扎染产品.该工艺不受套色限制,将印花、染色、扎染和压皱等方法融合在一起,提高了生产效率.     

决策树在风险管理中的应用分析

该文对决策树的原理、定义、特点、构成要素、应用步骤和应用场合进行了深入浅出的论述,并举例作了详细说明,对于应用决策树这一风险型决策方法具有一定启迪。     

B样条曲线的节点插入问题及两个新算法

Ｂｏｅｈｍ算法和Ｏｓｌｏ算法是Ｂ产条曲线的节点插入的经典算法，它们可以有效地将节眯插入到端点插值（Ｅｎｄｏｐｏｉｎｔ－ｉｎｔｅｒｏｌａｔｉｎｇ）Ｂ样条曲线，但是，对于其它的Ｂ样条曲线而言，当插入靠近节眯矢量两端附近的节点时，所有的经典算法都将出错，本文提出了两个节点插入新算法，它们可以解决节插入的经典算法中的问题，能够将任意节点插入到各种Ｂ样条曲线之中，它们的另一个重要用途是可以用于各种Ｂ样条曲线     

Approximation of multivariate functions and evaluation of particular solutions using Chebyshev polynomial and trigonometric basis functions

A two‐stage numerical procedure using Chebyshev polynomials and trigonometric functions is proposed to approximate the source term of a given partial differential equation. The purpose of such numerical schemes is crucial for the evaluation of particular solutions of a large class of partial differential equations. Our proposed scheme provides a highly efficient and accurate approximation of multivariate functions and particular solution of certain partial differential equations simultaneously. Numerical results on the approximation of eight two‐dimensional test functions and their derivatives are given. To demonstrate that the scheme for the approximation of functions can be easily extended to evaluate the particular solution of certain partial differential equations, we solve a modified Helmholtz equation. Near machine precision can be achieved for all these test problems. Copyright © 2006 John Wiley & Sons, Ltd.     

无结图及其若干性质

给出了结、无结图、有结图等概念，然后提出了图Ｇ０为无结图的充要条件，并论述了无结图的若干性质。     

Real-time accurate hand path tracking and joint trajectory planning for industrial robots(II)

Previously, researchers raised the accuracy for a robot’s hand to track a specified path in Cartesian space mainly through increasing the number of knots on the path and the segments of the path. But, this method resulted in the heavier on-line computational burden for the robot controller. In this paper, aiming at this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method for robots. Through selecting some extra knots on the specified hand path by a certain rule, which enables the number of knots on each segment to increase from two to four, and through introducing a sinusoidal function and a cosinoidal function to the joint displacement equation of each segment, this method can raise the path tracking accuracy of robot’s hand greatly but does not increase the computational burden of robot controller markedly. Foundation item: Foundation of the Robotics Laboratory, Chinese Academy of Sciences (No: RL200002) Biography of the first author: TAN Guan-zheng, Ph D, professor, born in Oct. 1962, majoring in artificial intelligence, robotics, and automation.     

管理链理论的探讨

借鉴了系统理论和可靠性理论的基础上，从管理实践中抽象出管理链理论。为正确评价一个组织的管理水平和提高其管理绩效，提供了一种新的便捷的方法。     

Knot placement for piecewise polynomial approximation of curves

For piecewise polynomial representation of curves, an algorithm to create knots is presented. The aim is to minimize the interpolation error for a given number of knots or, conversely, the number of knots needed to interpolate within a tolerance. The method used is a modification of de Boor's knot placement scheme. The algorithm described in this paper has been realized in the CADCAM system SYRKO, a Daimler-Benz development for car body design and manufacturing.     

环形腔微光纤MZI的海水温/盐度同时测量的设计与模拟

为实现海水中温度和盐度(温/盐度)同时测量,设 计了一种环形腔微光纤Mach-Zehnder干涉仪(MZI)。首先,计算了MZI在不同温/盐度下的 输出光谱,光谱中同时存在谐 振峰和干涉峰,分别由环形腔谐振和MZ干涉引起,由于谐振峰和干涉峰对温/盐度变化的响 应不同,因而 可将其运用于海水的温/盐度同时测量;其次,为了提升MZI的测量灵敏度,计算了灵敏度 与 其结构参数的关系。结果表明,谐振峰的温/盐度灵敏度只与制成环形腔的微光纤直径有关 ,而干涉峰灵敏 度同时与MZI两个微光纤臂的直径和长度相关,当制成环形腔的微光纤臂是MZI两臂中直径 较 小且长度较大的一臂时,能得到较高的测量灵敏度。经过优化后,干涉峰的温/盐度灵 敏度比传统的 光纤光栅分别提升了75倍和约3650倍。本文 设计的MZI具有结构简单、灵敏度高的优点,可为研制新型的海洋微光纤传感器提供参考。